Apparatus for molten metal supply changeover during casting



Nov. 23, 1965 NAMY 3,218,682

APPARATUS FOR MOLTEN METAL SUPPLY CHANGEOVER DURING CASTING Filed March19, 1963 5 Sheets-Sheet l GGGG MY 3,218,682

L SUPPLY CHANGEOVER DURI Nov. 23, 1965 NAMY 3,218,682

APPARATUS FOR MOLTEN METAL SUPPLY CHANGEOVER DURING CASTING Filed March19, 1963 5 Sheets-Sheet 3 G. NAMY 3,218,682

APPARATUS FOR MOLTEN METAL SUPPLY CHANGEOVER DURING CASTING Nov. 23,1965 5 Sheets-Sheet 4 Filed March 19, 1965 Nov. 23, 1965 N 3,218,682

APPARATUS FOR MOLTEN METAL SUPPLY CHANGEOVER DURING CASTING Filed March19, 1963 5 Sheets-Sheet 5 Fig.6

United States Patent APPARATUS FOR MOLTEN METAL SUPPLY CHANGEOVER DURINGCASTING Grald Namy, Saint-Etienne, Loire, France, assignor to ConcastA.G., Zurich, Switzerland Filed Mar. 19, 1963, Ser. No. 266,368

Claims priority, application France, Mar. 22, 1962,

891,898 Claims. (CI. 22-79) The invention relates to novel apparatus forthe continuous casting of metals, especially steel, and in particular tothe arrangement of ladles and distributor containers, over the ingotmold or die of a continuous casting machine.

In conventional equipment for continuous casting, a pouring ladle isarranged above the die or mold and supplies an intermediate containerwhich in turn enables feeding of the metal into the die.

Normally, the casting operation is initiated with a cold-slab or dummybar, which seals the die or mold at its base, prior to the casting, andis then pulled out downwardly and afterwards separated from the slabproper. When the pouring ladle is emptied the casting operation is theninterrupted and a cold slab is once again inserted, so as tore-commence, and continue the casting operation. This procedure involvesexcessive down time, particularly when casting slabs. In addition, thefirst portion of the cast strand, which follows the dummy bar and theend portion (i.e., the portion formed by the molten material maintainedin the mold as the feeding head) are discarded as scrap. This involvesthe loss of material. It has therefore been attempted, by a quickinterchanging of the ladles, or by the arrangement of two ladles,provided each with a feeding channel to a common intermediate containerto enable a quick change from an empty ladle to a full one. The proposedarrangement of two ladles on trucks, which successively pour into acommon container has the disadvantage, that these trucks requireexcessive space in the already confined space of the pouring-floor. Theintermediate container, must possess large dimensions, so as to form abuffer for the interrupted steel supply during the exchange of ladles.However, with this proposed arrangement the fabrication costs of theintermediate container are increased and the formation of slag isincreased. Moreover, a large intermediate container, has thedisadvantage of having a large heat radiation potential. Thisdisadvantage causes either an overheating of the fused steel mass, orrequires the installation of additional heating units on theintermediate container. The overheating of the fused steel mass causesdisadvantages in the form of increased wear of the ladles, the increasedaccumulation of slag, and substantially higher melting costs. Theheating appliance for the intermediate container renders the plantintricate and reduces the service life of the intermediate container. Ithas therefore been proposed to provide a quick interchanging device forthe intermediate container. However, the proposed structures revealeddisadvantages, in that the die and its suspension means were covered bydirt, when changing the intermediate container, by the steel stillflowing out or by the slag. Furthermore, the cleaning of the die and itssuspension is very difficult, because access is restricted.

Moreover, in the apparatus and processes known to the art, the materialand production losses have increased manufacturing costs. To preventinclusion of slag in the casting, which leads to the lack of homogeneityand production losses, the art has used large ladles. Although moremetal may be poured from a large ladle, to avoid inclusion of materialcooled below the casting tempera- 3,218,682 Patented Nov. 23, 1965 ture,changeover to another ladle must be made at a time when the first ladleholds a considerable amount of material. Thus, handling costs areincreased. Further, on changeover, the slag carried in the stream of thenew ladle enters the casting. Thus, the large ladles only decrease thefrequencies of faults in the casting at the expense of increasedhandling costs.

An object of the present invention is the provision of apparatus for thecontinuous casting of metals which eliminates the above mentioneddisadvantages. With this apparatus the liquid metal is directedsuccessively from containers via associated intermediate containers andtheir outlets in a casting mold or die. According to the invention themethod consists in placing, before emptying a first container, at leastone collecting device leading to an emergency ladle beneath the outletof an intermediate container associated with a second container, fillingthe second intermediate container and turning it with its collectingdevice into a position above the die, turning the collecting device fromthe outlet of the container and clearing the way for the jet of metal tothe die, simultaneously placing the collecting device associated withsaid first intermediate container beneath the outlet of this containerto divert its jet of metal into said emergency ladle, and then turningthe first intermediate container with its collecting device away fromthe die, the said turning movements of the intermediate containers beingsynchronized so that the supply of metal to the die is not substantiallyinterrupted.

This process enables the fully continuous casting of a faultless slab,since, during the changing of a ladle becoming empty for a full ladle,the intermediate container associated with the full ladle is filled, thecold steel and the slag in the intermediate container are drained by achannelof the collecting device, and in the appropriate moment, when thesteel flowing out of the intermediate container has reached the desiredtemperature, the chan nel can be removed from underneath this container,while the channel associated with the intermediate container of theempty ladle is placed underneath this latter container for collectingthe slag. During this procedure the two intermediate containers,together with their channels, are simultaneously positioned over the dieand moved away from the die respectively. It is therefore, practicallypossible to produce a casting which apart from influences of theparticular analytic composition, is of absolutely homogeneous structure,practically free of slag inclusions and solid throughout, and whichresults in a minimum waste. The intermediate containers can beinterchanged without soiling the die, or its suspension. Furthermore,since the intermediate containers can be of reduced volume andaccordingly the loss of temperature is small it is not necessary tooverheat the steel, and therefore the costs for the brick-lining of theladle and intermediate containers are reduced.

For carrying out the method according to the invention, provision ismade for at least two intermediate containers, each provided with atleast one outlet spout; each intermediate container is pivotally mountedon a suspension means and for each spout a channel is pivotally mountedon suspension means below each intermediate container. This arrangementhas'the advantage that the channels can be utilized not only whenchanging a ladle for another one, but also when a disturbance occursduring operation of the casting plant. According to a further feature ofthe invention, the intermediate containers and the channels aresupported on a common suspension means. This arrangement results in anexceptional simplification of the control, and in an economical, andsimple space, saving construction.

In a modification of the invention each intermediate container and itsassociated channel are pivoted on a common suspension means.

mounted on a truck which is movable in a direction transverse to thecasting axis.

This arrangement offers the advantage of eifecting repair andmaintenance of the intermediate containers and the channels outside ofthe casting floor and thus to keep the workmen concerned away from theimmediate vicinity of the casting machine.

Several embodiments of apparatus according to the invention areillustrated in the accompanying drawings in which:

FIGURE 1 is a side-view of an apparatus for continuous casting accordingto a first embodiment of the invention, partly drawn in section alongthe'line II of FIG- URE 2.

FIGURE 2 is a horizontal section taken along the line IIII of FIGURE 1,with the stoppers omitted.

FIGURE 3 is a view in elevation, partly drawn in section along the lineIII-III of FIGURE 1 with the left intermediate container removed.

FIGURE 4 is an illustration of the progressive dislocation of the moltenstreams from the various intermediate containers above the ingot mould.

FIGURE .5 is a view in elevation partly shown in section along the .lineVV o'f FIGURE 6 showing another embodiment of the invention.

FIGURE 6 is a plan view partly shown in section along the line VIVI ofFIGURE 5.

FIGURE 7 is a view in elevation partly drawn in section of theembodiment of FIGURE 6, with the left intermediate container removed.

FIGURE 1 shows an arrangement of two ladles 1 and 2 mountedsymmetrically to the casting axis, upon a stage 3 above a pouring fioor4. The ladles 1 and 2 can be lifted out, or lowered into the stage 3, bymeans of a crane 5. 'Two intermediate containers 6 and 7 are arrangedbelow the ladles 1 and 2. The containers are interchangeably positionedon frames 8 and 9. The frames 8 and 9 are pivoted on a pillar 10. Thepillar 10 runs parallel to the casting axis, and is. symmetricallypositioned to the ladles 1 and 2. With the assistance of their 'frames,which can turn through 360in the practise, 180 is sufiicient-t-heintermediate containers 6 and 7 can be turned to a bridge or similarplatform .(not shown), where they can be exchanged and/or pro-heated.The swivel-movement of the intermediate containers can be achieved forexample by cables 11 and 12, and by winches mounted on the stage 3.Other means can however be utilized to swivel the intermediatecontainers 6 and 7. Plugs 15 and .16 are arranged in the intermediatecontainers 6 and 7 to control the rate of pouring or to close the outletnozzles 17 and 18 (FIGS. 2 and 4). The movement of the plugs 15 and 16is controlled through compound lever systems 19 and 20 (FIG. 2).Channels 21 and 22 are .arranged .below the intermediate containers 6and 7. The channels are pivoted .on the pillar 10, and open into theslag containers 23 and ,24, which if need 'be, can overflow into anemergency ladle 25.

In FIGURE 3 an ingot mold or die 26 isshown, which can be supplied withliquid steel alternatively from the outlet nozzle 17 or 18 of theintermediate containers 6 .or 7. In FIGURE 2, the reference numerals 27and 28 mark the areas where the liquid steel which flows out from theladles 1 and 2, impinges upon the containers 6 and 7. In FIGURE 4, thechanging from one ladle to the other is schematically illustrated. Whenthe ladle 1 is almost empty, the ladle 2 which is inserted at thecorrect time by the crane 5 into the stage 3, starts to pour into theintermediate container 7. The chan- -nel 22, under the intermediateconatiner is driven beforehand under the spout 18. Theintermediate-container 7 is filled with liquid metal and the slag withthe too cold metal is diverted through the channel 22 into the slagcontainer 24. If an additional plug 16 is available,

This suspension means is as shown in the example concerned, then it willbe closed, as soon as the slag container is thoroughly rinsed, and thecold steel and slag have finished running-oil. After this theintermediate container 7, together with the channel 22 is moved in thedirection of the mold 26 into ready position. As soon as one observesthat the metal flowing out of the ladle 1, is no longer clean, i.e.,mixed with slag, the plug 16 is opened. The stream from the nozzle 18,is directed into the channel 22 until the stream has cleaned the nozzleand ceases to flap. Then the channel 22, is moved away from under themolten stream coming from the nozzle 18, and thereby, leaves the waytree for the molten stream to flow into the ingot mold. The channel 21is then simultaneously moved under the nozzle 17,and the steel comingfrom the intermediate container 6 at present not yet mixed with slag, isdirected through the channel 21, into the slag container 23. If no plugsare available, the steel flowing from the nozzle 18, will be directedthrough the channel 22, until the channel 21, can be brought under thenozzle 17. In this case, the intermediate container 7 is filled while inthe ready position.

FIGURE 4 illustrates the progressive transfer of the molten-streamswhich come from the nozzles 17 and 18 when inter-changing oneintermediate container for the other, whereby the lines m correspondwith the narrow side of the ingot mold 26.

Position a: preparation for casting, filling of the inter--mediate-container. The molten stream coming from the nozzle 17 is stillsituated in the casting axis A, whilst the molten-stream coming from thenozzle 18 is directed through the channel 22. The channel 21 stands inreadiness.

Position b: immediately prior to the change. The intermediate container7, together with the channel 22, is moved in the direction of thecasting axis, the molten stream coming from the nozzle 18 is still beingdirected through the channel 22. Simultaneously, the molten streamcoming from the nozzle 17 wanders away to :the right from the castingaxis owing to movement of the intermediate container 6. The moltenstream however still flows into the mold.

Position c: the moment of changing from nozzle 17 .to nozzle 18. Theintermediate container continues to be turned, whilst the turningmovement of the channel 22 is stopped (the channel 22 can also beremoved). Simultaneously, the intermediate container 6 is turned overthe channel21, and the molten stream coming from the nozzle 17 flowsinto the channel 21 (the channel 21 can also be turned under the moltenstream coming from the nozzle 17), whilst the molten stream coming vfromthe nozzle 18 flows into the die.

Position d immediately after the moment of changing. The channel'22remains still, whilst the intermediate container 7 is turned furthertowards the casting-axis. The intermediate container 6 ,is turned awayfrom the die together with its channel 21.

Position 2: the change is completely effected by 'the moltenstreamcoming from the nozzle 18, is in the desired place, whilst theintermediate container 6, together with the channel 21 is turnedfurther. As soon as all the steel and slag has flowed out of thiscontainer, it can then be turned away up to and more, from its originalcasting position. In this position, the container can be repaired orchanged. When this work is completed, the container may receive apre-heating device so as to keep it warm for the next casting operation.Likewise, repair-work can be undertaken on the channel 21. The ladle .1is lifted out of the stage 3 by 'means of the crane 5 and returned tothe steelworks to be filled in preparation .for the next casting. Onecould possibly omit completely the .use of ladies, and thus feed themetal direct from the furnace, via channels into the casting machine.

By moving the channel 21 or 22, it is possible in case of emergency, toimmediately discontinue the casting operation and to divert the steelinto the slag containers 23 and 24, and into the emergency ladle 25.

FIGURES 5, 6 and 7 show a modification of the invention. The ladles 30and 31 are interchangeable their frame, arranged above the die or moldand can be emptied into the intermediate containers 34 and 35. Theintermediate containers 34 and 35 are pivoted on pillars 36 and 37.These pillars are secured on trucks 38 and 39, which are movable onrails 40. The arrangement of the pillars 36 and 37, and the containers34 and 35 is so, that when being ready for casting the pillars 36 and 37are situated externally and the containers 34 and 35 internallyalongside one another (FIG. 6). The channels 41 and 42 are likewisepivoted on pillars 36 and 37, below the intermediate containers, andserve exactly as described in the first example, to direct the coldsteel and the slag, into the slag containers 43 and 44, and an emergencyladle 45. The change from an empty ladle to a full one is achieved asdescribed in the first example. The modified arrangement has theadvantage, that the intermediate containers can be brought further awayfrom the casting machine so that the immediate vicinity around thecasting machine is free of reserve intermediate containers, workingtools, etc. The change from one intermediate container to another iseffected as described for the first example.

Instead of the suspension arrangement of the intermediate containers andthe channels as shown in FIG- URES 5 to 7 it is possible to provideseparate suspension means for the containers and the channels should theconstruction of the machine necessitate this separation.

The arrangement of the suspension for the channel, either in front of oralongside of the suspension of the intermediate container, can possiblyofier certain advantages.

I claim:

1. Apparatus for changeover of the supply of molten metal being pouredinto a mold without introduction of slag or solidified metal into thepour during the changeover, comprising a mold, a first ladle of moltenmetal, a first intermediate container positioned below said first ladleto receive the molten metal flowing from said first ladle, said firstintermediate container being provided with a first outlet nozzle to poursaid received metal into said mold, a first channel positioned belowsaid first intermediate container and adjacent said first nozzle, asecond ladle of molten metal, a second intermediate container positionedbelow said second ladle to receive the molten metal flowing from saidsecond ladle, said second intermediate container being provided with asecond outlet nozzle through which said received molten metal flows, asecond channel positioned below said second intermediate container andaligned with said second outlet nozzle, said first and secondintermediate containers being rotatably mounted about vertical axes, andmeans for swinging said intermediate containers about the respectiveaxis simultaneously to position said first nozzle over said firstchannel and to position said second nozzle over said mold, thereby tochange the supply of molten metal flowing into said mold from said firstladle to said second ladle, said channels directing the flow of metalpoured therein to a repository so that slag introduced during changeoveris diverted from the mold.

2. Apparatus for changeover of the supply of molten metal being pouredinto a mold without introduction of slag or solidified metal into thepour during the changeover, comprising a mold, a first ladle of moltenmetal, a first intermediate container positioned below said first ladleto receive the molten metal flowing from said first ladle, said firstintermediate container being provided with a first outlet nozzle to poursaid received metal into said mold, a first channel positioned belowsaid first intermediate container and adjacent said first nozzle, asecond ladle of molten metal, a second intermediate container positionedbelow said second ladle to receive the molten metal flowing from saidsecond ladle, said second intermediate container being provided with asecond outlet nozzle through which said received molten metal flows, asecond channel positioned below said second intermediate container andaligned with said second outlet nozzle, said first and second channelsbeing pivotally mounted about vertical axes, and means for swinging saidchannels about the respective axis simultaneously to position said firstchannel underneath said first outlet nozzle and to move said secondchannel out of alignment with said second outlet nozzle, thereby tochange the supply of molten metal flowing into said mold from said firstladle to said second ladle, said channels directing the flow of metalpoured therein to a repository so that slag introduced during changeoveris diverted from the mold.

3. Apparatus according to claim 1, in which said intermediate containersand said channel means are all pivotally mounted on a common suspensionmeans.

4. Apparatus according to claim 1, in which each of said intermediatecontainers together with its associate channel means are pivotallymounted on a separate suspension means.

5. Apparatus according to claim 4, in which said suspension means areeach mounted on a truck which is movable in a direction transverse tothe axis of the castmg.

References Cited by the Examiner UNITED STATES PATENTS 2,202,702 5/1940Lindner et a1. 3,066,364 12/1962 Baier 2257.2

FOREIGN PATENTS 704,620 2/ 1954 Great Britain.

J. SPENCER OVERHOLSER, Primary Examiner.

MARCUS U. LYONS, Examiner.

1. APPARATUS FOR CHANGEOVER OF THE SUPPLY OF MOLTEN METAL BEING POUREDINTO A MOLD WITHOUT INTRODUCTION OF SLAG OR SOLIDIFIED METAL INTO THEPOUR DURING THE CHANGEOVER, COMPRISING A MOLD, A FIRST LADLE OF MOLTENMETAL, A FIRST INTERMEDIATE CONTAINER POSITIONED BELOW SAID FIRST LADLETO RECEIVE THE MOLTEN METAL FLOWING FROM SAID FIRST LADLE, SAID FIRSTINTERMEDIATE CONTAINER BEING PROVIDED WITH A FIRST OUTLET NOZZLE TO POURSAID RECEIVED METAL INTO SAID MOLD, A FIRST CHANNEL POSITIONED BELOWSAID FIRST INTERMEDIATE CONTAINER AND ADJACENT SAID FIRST NOZZLE, ASECOND LADLE OF MOLTEN METAL, A SECOND INTERMEDIATE CONTAINER POSITIONEDBELOW SAID SECOND LADLE TO RECEIVE THE MOLTEN METAL FLOWING FROM SAIDSECOND LADLE, SAID SECOND INTERMEDIATE CONTAINER BEING PROVIDED WITH ASECOND OUTLET NOZZLE THROUGH WHICH SAID RECEIVED MOLTEN METAL FLOWS, ASECOND CHANNEL POSITIONED BELOW SAID SECOND INTERMEDIATE CONTAINER ANDALIGNED WITH SAID SECOND OUTLET NOZZLE, SAID FIRST AND SECONDINTERMEDIATE CONTAINERS BEING ROTATABLY MOUNTED ABOUT VERTICAL AXES, ANDMEANS FOR SWINGING SAID INTERMEDIATE CONTAINERS ABOUT THE RESPECTIVEAXIS SIMULTANEOUSLY TO POSITION SAID FIRST NOZZLE OVER SAID FIRSTCHANNEL AND TO POSITION SAID SECOND NOZZLE OVER SAID MOLD, THEREBY TOCHANGE THE SUPPLY OF MOLTEN METAL FLOWING INTO SAID MOLD FROM SAID FIRSTLADLE TO SAID SECOND LADLE, SAID CHANNELS DIRECTING THE FLOW OF METALPOURED THEREIN TO A REPOSITORY SO THAT SLAG INTRODUCED DURING CHANGEOVERIS DIVERTED FROM THE MOLD.